The hierarchical radiation of phyllostomid bats as revealed by adaptive molar morphology

Curr Biol. 2024 Feb 29:S0960-9822(24)00169-6. doi: 10.1016/j.cub.2024.02.027. Online ahead of print.ABSTRACTAdaptive radiations are bursts in biodiversity that generate new evolutionary lineages and phenotypes. However, because they typically occur over millions of years, it is unclear how their macroevolutionary dynamics vary through time and among groups of organisms. Phyllostomid bats radiated extensively for diverse diets-from insects to vertebrates, fruit, nectar, and blood-and we use their molars as a model system to examine the dynamics of adaptive radiations. Three-dimensional shape analyses of lower molars of Noctilionoidea (Phyllostomidae and close relatives) indicate that different diet groups exhibit distinct morphotypes. Comparative analyses further reveal that phyllostomids are a striking example of a hierarchical radiation; phyllostomids' initial, higher-level diversification involved an "early burst" in molar morphological disparity as lineages invaded new diet-affiliated adaptive zones, followed by subsequent lower-level diversifications within adaptive zones involving less dramatic morphological changes. We posit that strong selective pressures related to initial shifts to derived diets may have freed molars from morpho-functional constraints associated with the ancestral molar morphotype. Then, lineages with derived diets (frugivores and nectarivores) diversified within broad adaptive zones, likely reflecting finer-scale niche partitioning. Importantly, the...

Source: Current Biology - March 6, 2024 Category: Biology Authors: David M Grossnickle Alexa Sadier Edward Patterson Nashaly N Cort és-Viruet Stephanie M Jim énez-Rivera Karen E Sears Sharlene E Santana Source Type: research